[RE-wrenches] paralleling FM-60's

[R Ray Walters]

Hi Jay;

I'd second (3rd, 4th?) everyone else's comments that it probably isn't a good idea.
I'd add that the diode will eat at least a volt, so that's not good for MPPT, or balancing.
The one possible way to do this, might be to use a Vanner battery equalizer, which is designed to split an incoming charge source, and feed 2 batteries, without letting them 
"see" each other. I think they're only good for 24 v, though, so that might not work for your situation. 
The only other way I could see, is using a huge relay ( or paralleled relays) controlled by a C40 (or similar). You would lose both MPPT and PWM, and be back in the solar stone age (90s) though.

TIme to pull out the 2 big cables, and pull 4 smaller ones?
Have fun, I actually like retrofitting old off grid stuff; it presents all sorts of interesting challenges like this.

R. Walters
ray at solarray.com
Solar Engineer




On Oct 20, 2010, at 9:06 AM, jay peltz wrote:

> HI All,
> 
> Say anyone ever paralleled mx/fm-60's?
> 
> I have a unique situation that would be very expensive to pull additional wire however the existing wire is large enough to need 2 fm-60s'
> 
> If I put a diode between them so they don't feed each other any problems that anyone knows of?
> 
> thanks,
> 
> jay
> 
> peltz power
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